The present invention relates to an apparatus for sorting and transporting sheets, an apparatus for automatically transporting original sheets and an automatic paper feeding apparatus. More specifically, the present invention relates to those apparatuses for storing a stack of sheets.
Japanese Patent Laying-Open No. 17359/1981, Japanese Patent Laying-Open No. 74263/1981 and Japanese Patent Laying-Open No. 159859/1985 are examples which disclose copy machines as conventional apparatuses which require the sorting of a group of stacked sheets.
The copying machines have a storing part for storing a stack of original sheets. The original sheet at the bottom of the group of the original sheets is transported by rollers and positioned at the exposure point of the copying machine. After exposure, the original sheet is transported by rollers and stacked on a stack of the original sheets. In this way, the original sheets are circulated from the storing part through the exposure point.
The copy machines produce a two-sided copy corresponding to two one-sided original sheets as in the following: First, all the even-numbered pages of the original, for example, are copied. The copy sheets are turned and fed again to copy the odd-numbered pages on the other side. Accordingly, these kinds of copying machines circulate all the original sheets when either the even-numbered pages or the odd-numbered pages are copied. Therefore, all the original sheets must be circulated twice to make each two-sided copy. That is, in the conventional copying machine, the odd-numbered pages of the original sheets are only transported, without copy processing, when the even-numbered pages are copied, and the even-numbered pages are only transported, without processing, when the odd-numbered pages are copied. This means the transportation of the original sheets is inefficient and the process speed is thus limited.
A copying machine disclosed in Japanese Patent Laying-Open No. 21073/1980 comprises an automatic original transporting apparatus having two original transport lanes. In this case, when an even-numbered page/sheet of the original is transported through a lane and copied, an odd-numbered page/sheet of the original is being transported through the other lane while the even-numbered page/sheet of the original is being exposed.
This copying machine, however, has only one exit in the storing part to the original transport lanes, so that only after a sheet of the original is completely transported out of the storing part can the next sheet of original begin to be transported. Further, according to the above constitution, the sheet of the original to be copied must be detained while the next sheet of the original is being transported. Therefore, the conventional copying machine can not transport the sheets of he original at high speed.